Mercury 850 water coming out exhaust?

[bryanwess2000]

I still have water coming out my upper exhaust( just below the cowling)
after replacing the 2 exhaust cover gaskets. The only thng I didn't do was use the anticorrosion grease since I had some pretty bad areas of corrosion I had to use some gasket sealant/maker to fill in these areas. then I torqued each bolt to 250 in/lbs in sequence x2. The water pressure from the pee line increased dramatically but there is still water coming out the exhaust. Any Ideas what I did wrong or can do to fix this? I'm hoping to gat a few more years out of this motor.

 

[corm]

Re: Mercury 850 water coming out exhaust?

Hi,

If your talking about the two rectangle holes in the upper rear of your midsection just below the cover that hides the nuts and studs that hold your powerhead on well...that's normal. There should be a mist coming out of them.

 

[bryanwess2000]

Re: Mercury 850 water coming out exhaust?

Those are the ones, shows how much I know. Boy thats a relief I thought
I may have made a mistake in the reassembly. I haven't seen any other
mercury inlines running at the lake I go on so I had nothing to compare it to.
I'm using a clymer manual so I was unable to tell if this was normal since they
cover such a broad range of engines. Thanks for the fast reply.

 

[Fuzzytbay]

Re: Mercury 850 water coming out exhaust?

Those are the ones, shows how much I know.

There are no dumb questions, except the ones we don't ask.


.
I'm using a clymer manual so I was unable to tell if this was normal since they
cover such a broad range of engines.

Good manuals ARE a good investment.

 

[jumboshrimp]

Re: Mercury 850 water coming out exhaust?

Thats a relief Bryan was wondering what prop is working for you as (I have the '77 850 Thunderbolt 4cyl too) I have replaced my lower with a unit from a 100hp w/prop but it needs to be changed. What kind of speed are you getting with your vessel. Thanks

 

[bryanwess2000]

Re: Mercury 850 water coming out exhaust?

I'm running a 21p prop that looks like it's been cut down to about 12.8'' measured with a dial caliper, I don't know if the pitch has been altered.
The boat was running 37.5mph gps but this was with 30* timing which I
have decreased to 25-26* and now runs 36mph. My lower unit has 2.33
gears yours may be different in which case you'll need a lower pitch prop.
You can check by pulling your spark plugs, put the control in forward gear then line one of the blades of your prop with the trim tab mark that blade
with a marker then mark your flywheel and timing cover. Turn the flywheel
counting how many turns it takes to spin the prop one revolution exactly.
Your LU is probably has 2.0 gears in which case you would probably need a 17p or 19p prop.

 

[corm]

Re: Mercury 850 water coming out exhaust?

Thats a relief Bryan was wondering what prop is working for you as (I have the '77 850 Thunderbolt 4cyl too) I have replaced my lower with a unit from a 100hp w/prop but it needs to be changed. What kind of speed are you getting with your vessel. Thanks

Hi,

The 85 had 2.3 to 1 gear ratio LU the 100 HP LU has a 2 to 1 gear ratio.
Because of the difference in ratios you will have a little less torque so you will probably need one size smaller prop than you used to used on the old unit.

 

[SS Ice Cream Paint Job]

Re: Mercury 850 water coming out exhaust?

i have alot of water coming out of the exhaust ports and no water coming out of the pee hole???

 

[bryanwess2000]

Re: Mercury 850 water coming out exhaust?

ss unscrew the 90* elbow off the cylinder block cover then check to see if
water comes out, your "pee" hose or fitting at the end might be clogged